In the past, a user had two options for creating documents. One option was to use a word processor with rich text formatting capabilities, which allowed the user to shape the appearance of the documents to fit her needs. However, this type of word processor was not designed to associate semantics with content, such as using markups in the documents. The other option was to use a plain text editor, which required the user to manually create the markups along with the content. The disadvantage of using a text editor was that the user could not control the presentation and layout of the documents. Also, markup creation was typically done manually with very little automated assistance from the text editor to make the editing of markup documents easier to perform. One type of such popular markup documents are Extensible Markup Language (XML) documents.
XML is a universal language that provides a way to identify, exchange, and process various kinds of data. In order to provide greater transportability, the syntax of XML documents, which is defined by an XML standard, is extremely regular and predictable. An XML document that conforms to the XML standard is considered “well-formed.” XML documents are comprised of XML elements. An XML element typically takes the form of “<element>content</element>”, where the portions within brackets (<>), also known as “tags”, define the beginning and end of an element, and the portion between the brackets is the content of the element.
Even though practically every XML tag takes this same form, traditional text editors and word processors require the user to manually enter every character, opening the door to much human error. In addition, because neither traditional word processors nor text editors includes automatic XML validation mechanisms, any structural error in the XML coding is likely to go unnoticed. Moreover, the rigid nature of XML structure is completely antagonistic to the freestyle editing, text formatting, and layout control, which are the touchstone of good word processor.
Recently, XML editors have become available for editing documents in XML. Because these conventional XML editors are specially designed for editing XML documents, they strictly adhere to the XML structure. These XML editors make XML markup easier to manage than a plain text editor, but they impose restrictions on its user that prevent him from freely editing and formatting a document, as allowed by traditional word processors. Rather, the user is trapped in an editing environment where the structure of XML controls how content is edited in the document. This makes for a poor user experience, especially if the user desires to tailor the visual aspects of the document.